In 5G and other cellular systems, core-network services are provided by network functions (NFs). In some systems, NFs are configured with network hostnames or addresses of NFs with which they may need to communicate. In other systems, provider NFs register with a registry device, such as a 5G Network Resource Function (NRF). A consumer network function (NF) that wishes to use the services of a provider NF requests network information of that provider NF from the registry device. However, individual provider NFs may not always provide uniform levels of service, e.g., due to overload or to events affecting network connectivity.